Saw this in operation in Rio ..
http://www.alstom.com/products-services/product-catalogue/rail-systems/Infrastructures/products/aps-ground-level-power-supply/
rdamonSaw this in operation in Rio .. http://www.alstom.com/products-services/product-catalogue/rail-systems/Infrastructures/products/aps-ground-level-power-supply/
Little difference in principle between this and the pre-WWI GE systems that powered only the contacts under a car requesting power. In fact, if I recall correctly, at least one of the GE designs used technically-RF induction and not just energized DC electromagnets to 'pull' the power relays on, making it for all intents and purposes a 'wireless' (e.g. radio) system.
Naturally if you code the system like a garage-door opener, there is much less chance of accidental energization than if you were to use simple proximity (like the sensing in some of the inductive-charging arrangements) or simple RF handshaking arrangements. I have not looked carefully at the APS patent specs, but I wouldn't be surprised to find that security and prevention of malicious tampering were major features of the present design.
It doesn't hurt that solid-state relay design gives a much more robust and reliable product for switching traction voltage than the technology GE had to use 'back in the day'...
tree68 RME Of course, if you stepped wrong and shorted the DC across your lower body,
RME Of course, if you stepped wrong and shorted the DC across your lower body,
As some have called those who got fried, A Crispy Critter.
ORNHOO This year's snowpocalypse seems to be bringing the usual problems to electric traction systems; increased tension due to cold weather, ice buildup on conductors, etc. In good weather conductors on pantographs are subject to wear and need frequent replacement. Has anyone built a system where electricity is "harvested" from the caternary by electromagnetic induction without direct physical contact?
This year's snowpocalypse seems to be bringing the usual problems to electric traction systems; increased tension due to cold weather, ice buildup on conductors, etc. In good weather conductors on pantographs are subject to wear and need frequent replacement. Has anyone built a system where electricity is "harvested" from the caternary by electromagnetic induction without direct physical contact?
The 'constant tension' catenary systems which use counterweights are the correct solution to the first problem.
The exchange of graphite collectors on pantographs is not a major cost/problem, as far as I know. Contactless energy transfer is quite limited for mainline traffic at the moment, and it is practical only on tram/light rail applications (with covered inductive conduits etc., in a very short distance from the collectors)
N.F.
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